Marketing and acquisition
Return on investment (ROI) calculator
Return on investment is the profit an investment produced expressed as a percentage of what it cost. Subtract the cost from the gain, divide by the cost, and multiply by 100.
Profit produced, not revenue
Everything you put in, including staff time
The formula
- Gain
- The profit the investment produced, measured over the same window as the cost. Use profit rather than revenue. Putting revenue here while cost holds only the campaign spend leaves the cost of delivering the product out of the calculation entirely, which is how a campaign shows a healthy ROI and still loses money. For cost-saving investments, gain is the money you no longer spend.
- Cost
- Everything the investment required, not just the invoice. Ad spend plus the agency fee plus the hours your team put into creative. Software license plus implementation plus training. The instinct is to count only the line item that shows up in accounting, and it flatters the result every time. Tagging campaigns properly with a UTM builder is upstream of every marketing ROI number worth quoting.
A worked example
A distributor commits 10,000 to a trade show. The booth and freight are 6,500, travel is 2,000, and staff time accounts for the remaining 1,500. The show produces four orders worth 15,000 in gross profit over the following quarter.
Gain minus cost is 5,000. Divided by the 10,000 cost that is 0.5, and multiplied by 100 the ROI is 50 percent. Every dollar committed came back with fifty cents on top of it.
Now leave the staff time out, which is how this would usually get reported, on the reasoning that those people were salaried anyway. Cost drops to 8,500 and ROI climbs to about 76 percent. The show did not get better. Neither figure is arithmetically wrong, but only one of them can be compared to the next thing you measure, so the rule matters more than the result. Decide what counts as cost, write it down, and apply it every time.
When to use it
ROI is at its best comparing options of similar size and duration. Two trade shows, two pieces of equipment, two campaigns that ran the same quarter. It gives a single figure anyone in the room can read without a finance background, which is why it survives in board decks long after more precise measures have been proposed.
Anything above zero means the investment returned more than it cost, and below zero means it did not. That is the only reading that holds universally. Beyond it, treat any source offering a benchmark with suspicion. Forty percent is excellent for a twelve-month capital project and dismal for a two-week campaign.
It also works as a threshold rather than a ranking. Many operators set a floor, discard anything projected below it, and use the calculation as a filter. That works well when the alternatives are genuinely comparable and badly when they are not.
Where it misleads
ROI says nothing about time. A 50 percent return over one month and a 50 percent return over five years read identically, and one of them is a very good year while the other is barely worth the paperwork. Always pair the figure with a period, and for anything longer than a year use the CAGR calculator instead, which folds duration into the number itself.
It says nothing about when the money comes back either. Two investments can post identical ROI while one returns capital in three months and the other in three years. If cash position matters, and for most small organizations it does, payback period is the more urgent question.
It says nothing about scale. A 200 percent return on 500 spent and a 20 percent return on 400,000 are not the same opportunity, and a percentage alone will steer you toward the smaller one. Read ROI next to the absolute profit, not instead of it.
Finally, it is only as honest as your attribution. For marketing the gain figure usually rests on a chain of assumptions about which revenue came from which effort. ROAS narrows the question to advertising alone, which makes the attribution problem smaller and the number more defensible.
Frequently asked
What counts as a good ROI?
There is no universal figure. It depends on the period, the risk, and what else you could have done with the money. The practical test is whether the return beats your next best use of the same capital over the same window.
Should ROI use revenue or profit as the gain?
Profit, in almost every case. Using revenue inflates the figure by the entire cost of delivering the product, which is why a campaign can show a healthy ROI and still lose money.
Can ROI be negative?
Yes. A negative ROI means the investment returned less than it cost. Minus 100 percent means the entire amount was lost.
How is ROI different from ROAS?
ROAS divides revenue by ad spend and is expressed as a ratio, so it measures only the advertising. ROI subtracts total cost from total gain and is expressed as a percentage, so it can cover an entire initiative.
Numbers are the easy part
Getting the calculation right takes two inputs. Getting an organization to agree on what counts as gain, what counts as cost, and what the number should change takes considerably longer.
That translation work is most of what I do. Westphal Solutions builds websites, tools, and reporting for nonprofits and growing teams, including the kind of measurement setup that makes a number like this one worth trusting in the first place.
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